Electric-dipole active two-magnon excitation in {\textit{ab}} spiral spin phase of a ferroelectric magnet Gd${}_{\text{0.7}}$Tb${}_{\text{0.3}}$MnO${}_{\text{3}}$

N. Kida, Y. Yamasaki, R. Shimano +2

A broad continuum-like spin excitation (1--10 meV) with a peak structure around 2.4 meV has been observed in the ferroelectric $ab$ spiral spin phase of Gd${}_{0.7}$Tb${}_{0.3}$MnO${}_3$…